An International Data SIM card is a prepaid SIM card that allows users to make and receive calls, text messages, and data connections in more than 180 countries around the world. It's perfect for travelers who need a way to stay connected without having to worry about expensive roaming fees. Plus, international data SIM cards come with a variety of add-on features, like VoIP and VPN services, that can help you stay connected while you're out of the country.